The present invention is in the technical field of fluid distribution equipment. More particularly, the present invention is in the technical field of equipment performance monitoring and analysis of fluid distribution equipment.
A significant part of America's infrastructure concerns the transport and distribution of fluids. These long-distance distribution systems include municipal water utilities, wastewater systems, petroleum pipelines, and agricultural irrigation systems. There are also many short-distance systems, such as those used in oil refineries, water treatment plants, wastewater facilities, chemical plants, and even area-wide heating and cooling facilities. These distribution systems are comprised of different types of equipment, such as pipes, valves, pumps, storage tanks, wells, filters, sensors, and control systems. Sometimes these systems are operated by automated supervisory control and data acquisition (SCADA) systems. Other systems are operated manually by humans that may be located remotely.
These systems are critical to the country's health, security, and economy. Yet they are all subject to failures. They are expensive to build, operate, and maintain. The construction cost of a new pump station can be from $100,000 to over $1B, in 1999 dollars. The EPA estimates that energy usage accounts for 85 to 95% of the cost of operating a pump station. The cost of maintaining the equipment can be 3 to 15% of the pump station annual cost. The failure of a water or sewer main can easily result in millions of dollars for repair. These costs will be much higher if the fluid is gasoline or a hazardous chemical. Due to the high cost of building new infrastructure, the preferred strategy is to increase the efficiency of the equipment and to extend the lifetime of the equipment as long as possible.
Pipeline failures can usually be attributed to one of three causes: 1) accidental damage from collisions or construction equipment, 2) corrosion, 3) incorrect operation of connected equipment by human or automated control.
Accidental damage usually results in a catastrophic break in the pipe. This can be detected by a rapid decrease in pressure or flow through the pipe. This is a very rare occurrence and requires constant monitoring of the pipes. The process either generates a lot of data that must be transmitted and analyzed, or often results in a delay in response due to long sampling intervals.
The following patents cover systems and methods for detecting catastrophic failures in pipelines:
U.S. Pat. No. 4,796,466 discloses a system for monitoring pipelines. This is a computerized system that uses statistical techniques to continuously analyze a pipe to detect a rapid decrease in pressure or flow. The system does not record data, but instead, outputs a signal that can be used to notify operators of a problem.
U.S. patent application No 20090115424 discloses an apparatus and method for detecting faults in tanks. It measures the length of time that a pump runs to fill the tank. If there is a significant difference in the length of the pump cycle, a warning is issued.
Corrosion happens over a long period of time, resulting in slow leakage until a catastrophic failure occurs. This is often detected by monitoring a gradual decrease in pressure over a long period of time.
The following patents cover systems and methods for detecting small leaks in pipelines and other equipment:
U.S. Pat. No. 9,134,160 discloses an online multi-phase flow meter system. This system continuously measures the volume of water, gas, and oil flowing concurrently in a pipeline. The system continuously adjusts for differences in flow rate to maintain consistent sampling.
U.S. Pat. No. 5,739,420 discloses a system for detecting ground water infiltration. The system looks for leaks in a pipeline by inserting a probe into the pipe at manholes and tracking its location from the surface of the ground. Properties are recorded at different geographic locations and later analyzed.
U.S. patent application No 20120232750 discloses a system to monitor the transport of fluids. The device continually monitors the level and pressure of fluid in a truck-mounted tank. Measurements are recorded including time and geographic location to determine if leaks have occurred.
Incorrect operation of connected equipment, such as valves and pumps, can cause stresses that are not immediately damaging. Opening and closing a valve in the system can cause very rapid changes in pressure (known as transient pressures) which may be outside of the design safety limits of the equipment. These changes can last from a few milliseconds to several minutes. These transients can also be caused by power failures that result in rapid shutdown of pumps. Either of these cases can be caused by human operators or a failure in the control system. Typical SCADA systems do not sample fast enough to detect these changes in pressure. In addition, the problem may actually be better detected by monitoring the quality of the power going to the equipment.
The following patents cover systems and methods for detecting transient pressures in pipelines:
U.S. Pat. No. 7,357,034 discloses a dynamic transient pressure detection system. This is an apparatus that continuously monitors pressures in pipelines and containment vessels. The pressure is recorded at a low speed and each sample is statistically examined for a deviation from the normal pressure. When a transient is detected, the recording speed is increased. When the pressure is no longer determined to be part of a transient, the recording rate is returned to a slow speed. Analysis of the data is performed manually.
U.S. Pat. No. 9,568,391 discloses a pipeline monitoring unit and method. This apparatus is used to detect transient pressures in pipelines. The unit measures the pressure at a high sample rate and statistically determines if it is part of a transient. If it is, it is recorded at the sampling speed. If it is not part of the transient, periodic samples of the pressure are recorded at a slower speed. The data are analyzed remotely.
U.S. patent application No 20090000381 discloses an acoustic impact detection and monitoring system. This system inserts multiple hydrophones into a pipeline to detect abrupt sounds, which may be an indication of a pressure transient. The system calculates the time of arrival at the different hydrophones to attempt to locate the source of the transient.
Failures can also occur in equipment such as pumps and valves, just as they do in pipelines. Mechanical wear and stresses are more likely to occur than damage from corrosion. Catastrophic pump failures can be determined by monitoring pressure and flow rate, just as in pipes. But detecting conditions that cause these failures usually requires monitoring over long periods of time. Increases in bearing temperature, current draw, and vibration are indications of a potential failure. Electrically and hydraulically operated valves have similar problems and can be monitored in the same way.
The following patents cover systems and methods for monitoring and control of machinery:
U.S. Pat. No. 6,567,709 discloses an integrated monitoring, diagnostics, shutdown, and control system. This system remotely monitors the condition of rotating machinery. It uses multiple sensors to determine a control output to be sent to the machine controller. The parameters of the machine controller are altered automatically.
U.S. patent application No 20050093191 discloses a system and method for monitoring the operation of an injection molding machine. While not equipment used in fluid distribution, it does include the operation of pumps and valves. The system measures pressure and flow rate in the injection cylinder. The system analyzes the sensor readings, calculates appropriate control parameters, and adjusts the machine accordingly.
U.S. patent application No 20090105969 discloses a method and device for the assessment of fluid collection networks. This apparatus is used to monitor the fluid flow in an open-channel distribution network, such as a sewer system. An accelerometer and a pressure sensor are installed on a float that rides on top of the fluid. The readings are recorded for later analysis.
Chinese Pat. No CN106680574 (A) discloses a system to sense over-voltage conditions in electrical substation equipment. The system independently uses sensors to monitor the conditions in transformers. These readings are compared to results of simulation and waveform analysis to determine if the equipment has reached the end of its useful life.
U.S. Pat. No. 4,999,117 discloses an apparatus and method to monitor a wastewater pump station. The performance of the pump station equipment is determined by measuring the change in the level of fluid in the wet well over time, during periods when the pump is running and when it is not running. The differences in changes are compared to known performance levels and alarms are issued as appropriate.
Failures in electronic control systems (SCADA) are much harder to detect, but can lead to the same failures in equipment. The control system may fail to send signals to the equipment, or may be sending inappropriate signals. This could be the result of control failure, incorrect control programs, or intentional malicious actions. The only way to detect these problems is to monitor the actual performance of the end system.
The following patents cover systems and methods for monitoring control systems:
U.S. Pat. No 6,764,019 discloses a method for servicing and maintaining heat supply equipment. This method uses a computer connected to a boiler control system that sends data to a remote computer for display and analysis. Maintenance personnel evaluate the data and make decisions.
Korean Pat. No. KR20170040478 (A) discloses an apparatus for life evaluation of pump mechanical seals. The apparatus collects data from sensors connected to the pump and compares the readings to a simulation of the pump seal under various conditions. This is for quality testing during manufacturing and not for monitoring fielded equipment.
Chinese Pat. No CN106817398 (A) discloses an embedded equipment monitoring and alarm system. This system is built into an industrial controller to monitor a process. The results of the monitoring are sent back to the controller to adjust its operation. This is not an independent monitoring system.
U.S. Pat. No. 9,797,785 discloses a method for monitoring environmental conditions. This is a system for monitoring the conditions in a climate-controlled environment. Sensors are located in the environment, such as a cold storage facility, and the readings are sent to a remote location for analysis. Alarms are displayed at the remote site.
U.S. patent application No 20150365303 discloses a method for analyzing SCADA systems. This system uses independent computers to capture the outputs of a SCADA system. The outputs are compared to the design specifications of the system to determine if the system is installed correctly. It does not monitor the actual operation of the SCADA system in use.
U.S. Pat. No. 9,785,142 discloses an apparatus and system for data processing in SCADA systems. This system gets the current readings from the SCADA system and determines the state of the equipment by comparing to a library of known states. Alarms are determined from the state. This system monitors the state of the whole installation, but is not independent of the control system.
International patent application No WO2017138948 (A1) discloses a method to automatically set parameters of process monitoring equipment. This method uses simulation of production processing equipment to set the control limits of the monitoring systems. The simulations predict the degradation of the equipment over time and calculate how the monitoring equipment should be modified. This is not a control system, but is used to configure the control equipment.
U.S. Pat. No. 6,353,804 discloses a method of statistically predicting equipment performance. The method consists of entering data collected from a mechanical device into a simulation of the device to create a set of equations specific to the equipment. These equations are used to generate a probability of the equipment's performance. This is not a monitoring system, but is used to evaluate performance based on measurements.
The QarVision Remote Elevator Diagnostic System by Qameleon Technology, Inc. is an example of a monitoring and diagnostic system that operates independently of a control system to analyze the performance of machinery. QarVision uses its own sensors to determine if an elevator is behaving in a way that the controller should be telling it to. It is a stand-alone, self-contained equipment analyzer that issues reports and alarms directly to maintenance personnel.
Reducing the consumption of energy will have the biggest impact on the cost of operating a fluid distribution system. Energy consumption is easily measured with power metering equipment. However, determining the relationship between energy and the efficiency of the complete system is not easy. Other factors that can affect the energy consumption in a system include obstructions in pipes which cause pressure increases, clogged air relief valves that reduce flow rate due to air in pipes, and fluctuations in incoming voltage that cause motors to run erratically.
The following patents cover systems and methods for monitoring system costs:
U.S. Pat. No. 7,398,184 discloses a system for analyzing equipment performance and optimizing operating costs. This system uses sensors to determine the level of corrosion in equipment and determine its effect on the life of the equipment. This information is used to determine the lifetime cost of operating the equipment.
U.S. patent application No 20120215464 discloses a system to monitor energy consumption. The system combines sensors with readings from power meters to determining the cost of energy being used. These readings are compared to predetermined limits for making decisions.
Very often determining how well a complex system is performing involves the use of multiple sensors that take measurements from different pieces of equipment and performing analysis of the total system. Most monitoring systems limit themselves to a single parameter, such as the pressure in a pipeline, when the actual cause of a problem may come from an entirely different source. The complete fluid distribution system could itself be considered one entity.
The following patents cover systems and methods for monitoring entire systems:
U.S. patent application No 20170117064 discloses a system for collecting data from a nuclear power plant. The system communicates information for control computers, sensors, workers' hand-held devices, and operational documents to a remote site. A computer at the remote site evaluates the data, and generates reports which are sent back to the plant. This is not a self-contained or real-time system.
U.S. Pat. No. 6,753,186 discloses a system and method for monitoring water quality. The system utilizes chemical analysis equipment at residences within a water system. The water quality is determined and generates local alarms if there is a problem. These measurements are also transmitted to a central monitoring station where readings from multiple residences are analyzed. This provides an overall measure of the water system's operation.
U.S. statutory invention registration No H613 discloses a portable shipboard gunnery diagnostic apparatus. This device is used to determine the effectiveness of a gun to hit a remote target. The system uses sensors at the gun to measure velocity and information communicated from the target area. The measurements are analyzed to recommend to the crew how to better operate the gun.
U.S. Pat. No. 7,139,564 discloses a wireless communication device for field personnel. The device, such as a personal digital assistant or laptop computer, is used by field personnel to enter information about the operation of an HVAC system. This information may include readings from instruments, visual information about the equipment, and customer information. This is sent to a central computer for logging and analysis. The results are sent back to the field personnel. This system does not involve automatic collection of sensor measurements.
U.S. Pat. No. 7,818,071 discloses a method for controlling and/or optimizing production of oil and gas wells. The system collects sensor data for wells, pipelines, seismic monitoring equipment, and other sources, and sends them to a central location. The data are analyzed by a team of experts that makes recommendations for controlling processes at the remote facilities. These instructions are then sent back to the remote facilities. This is not an automated process.
Data logging systems are widely used to monitor equipment, including fluid distribution equipment. They usually consist of one or more sensors connected to a small computer that records raw data in an internal memory. Some of these systems have a means to transfer data to another device, such as a laptop computer. Others may have a means to communicate with a remote system. While most use traditional sensors, there are systems that have unique mechanisms for collecting information.
The following patents cover systems and methods for data collection and recording:
U.S. Pat. No. 5,870,140 discloses a system for remote meter viewing and reporting. This is a system that uses a camera to take images of a physical meter, such as a power meter, and then sends the image to a remote computer for analysis. The remote computer converts the image to a measurement which is used to create a customer bill. The data being stored and communicated are the raw pixels from the camera.
U.S. Pat. No. 6,691,068 discloses an apparatus and method for obtaining process data. This device is a sensing and data storage system built on a silicon wafer that is loaded into processing equipment. The device takes measurements of the process which can be later analyzed to optimize the wafer production parameters. This is an independent, in-situ device with communication capabilities.
The SpikeWatcher Change Detection System by Qameleon Technology, Inc. is an independent device that combines transient signal detection with long-term, multiple sensor recording. It has the ability to communicate with external devices and systems using the interne and wired or wireless communication mechanisms. It also has the ability to be reconfigured remotely for different purposes in the same installation. A technician may decide to focus the monitoring on power consumption for a period of time and then switch the focus to vibration and temperature. However, this system only records data. Any analysis must be performed at a remote site using manual and programmatic means.
The need exists for a system to continually monitor and analyze equipment in critical infrastructures. The system needs to be independent of the existing equipment and any control system, focusing instead on the actual performance of the equipment. It should be easy to install in remote locations without interfering with the fluid distribution system itself. It should be self-contained, able to operate autonomously for long periods of time, be tolerant to failures in communications and power, and be resistant to electronic attacks. The Apparatus for Analyzing the Performance of Fluid Distribution Equipment described herein addresses these needs.